1. Technical Field
The present invention relates to an accumulating apparatus for accumulating continuous sheet supplied from an upstream apparatus while continuously feeding the continuous sheet to a downstream apparatus.
2. Description of the Related Art
Conventionally, a system where various processes are applied to continuous sheet while the continuous sheet is continuously conveyed to continuously manufacture products such as disposable diapers, is in practical use. In such a system, an accumulating apparatus is provided between an upstream supplying apparatus for drawing continuous sheet from wound sheet where the continuous sheet is wound like a roll (hereinafter the wound sheet is simply referred to as a “wound roll”) and a downstream manufacturing apparatus for sequentially applying processes to each portion of the continuous sheet.
In the accumulating apparatus, a plurality of upper rollers are located topside in a vertical direction and a plurality of lower rollers are located downside in the vertical direction. The continuous sheet is held in contact with the upper rollers and the lower rollers alternately to be conveyed, and therefore the continuous sheet supplied from the upstream supplying apparatus is accumulated while being continuously fed to the downstream manufacturing apparatus. When the remaining amount of the continuous sheet in the wound roll becomes low, supply of the continuous sheet from the supplying apparatus is stopped and a distance between the upper rollers and the lower rollers is decreased to keep feeding the continuous sheet to the manufacturing apparatus (see, for example, Japanese Patent Application Laid-Open No. 7-137899). Then, the continuous sheet is cut from the wound roll and spliced to an end of continuous sheet of a new wound roll in the supplying apparatus, and therefore it is possible to switch the wound roll with the low remaining amount to new wound roll, without stopping the downstream manufacturing apparatus.
In the above accumulating apparatus, the distance between the upper rollers and the lower rollers can be changed by moving the upper rollers or the lower rollers in the vertical direction. However, since normally the weights of the rollers are large, a mechanism for moving the rollers in the vertical direction becomes large in size and also manufacturing costs of the accumulating apparatus increase.